Home theatre systems: A buyer's guide

by Mahananda Bohidar

A mini-component or table-top stereo system can never deliver the kind of acoustics that an amp-aided speaker setup will.

Looking to upgrade your audio/ video experience and have to choose a high-def home theatre system? Or are you setting one up for the first time? You have saved up enough for a swanky new HTS, but is all the jargon involved in choosing the right pair of speakers or amplifier getting to you? Here's a low-down on what you should be looking out for when you step out to pick up new gear for a home theatre.

Why a home theatre system?

A stereo system or a mini-component system does suffice your need to listen to your favourite tracks and watch movies, but only the quality and experience delivered by a home theatre system is worthy of satisfying a true audiophile. A mini-component or table-top stereo system can never deliver the kind of acoustics that an amp-aided speaker setup will. Let's take a look at the different kinds of surround speaker set-ups you can opt for.

Speaker Set-up
While the most basic form of a home theatre sound system would be a 5.1 speaker system, you can push up the aural experience in your living room or mini-theatre with a 6.1, 7.1, 9.1 or even 11.1 systems. The last two are yet to gain popularity due to the lack of sources (CDs and DVDs) formatted for a 9.1 or 11.1 set-up. So, the 7.1 is your next-best option.

To have an idea of why you need these certain set of speakers, here's an example of the 7.1 set up. In a 7.1 set up, two speakers are placed on either side of your display unit primarily for playing back the music tracks.A third speaker stays at the centre, placed above or below the display unit, which relays voice or dialogue tracks. The last two units go to the rear of the seating space and are only for ambient sound effects that have been recorded on to your source. The other two speakers are for left and right surround placed just above ear level on either side of the seating area.

The sub-woofer also known as the LFE channel (Low Frequency Effects) helps capture all the low-frequency (bass-effect) sounds for you to feel it rather than hear it. For example, when there is thunder on-screen you'll feel the vibration while you hear the sound effect though the speakers.

Simplifying Speaker Specs
Some of us audiophiles are unfortunately averse to the seemingly undecipherable numbers printed on the speaker boxes. Here's a simplified narration of what they mean and what factors you should be looking for while picking up a pair or a HT set.

Power rating - The power rating of a speaker denotes the level of current it'll be able to take to function without any distortion. Here, there are two terms that you'll usually come across – PMPO and RMS.

PMPO (Peak Music Power Output) is what you'll see prominently flashed across hoardings and product packaging, especially in lower-end speaker packages. But, this is a marketing gimmick, the significance of which can be misleading. PMPO stands for the peak power capacity of amplifiers and speakers – the maximum load they can take for an instant under ‘perfect' conditions and is often bunched together for the whole speaker set. Hence, this value has little significance in real time and for extended periods of playback, which is what a home theatre system is meant to do.The more accurate measure is the RMS rating because it's an average of how much power the speaker can handle, usually referenced to indicate the level per channel or per speaker.

Sometimes the minimum power rating to make the speakers function is also mentioned. This, however, is something that you don't need to worry about as even the most basic amplifier will provide the minimum amount of power required to power them.

Impedance – A speaker with lower impedance will allow more current to flow through it, hence resulting in loud volumes.

Why should you keep this in mind? If your amp isn't designed to handle speakers with low impedance (4 ohms), then the amp may overheat (as it draws more current) when you turn the volume up very loud – thereby causing it to trip. The usual numbers you will see on speaker packaging is 4, 6 or 8 ohms, these being the estimated averages because impedance keeps varying constantly (in many amps, not all). Impedance has little to do with the quality of sound but it should be kept in mind to make the amp-speaker set-up run smoothly without any trips or power overload.

You can get a set of quality high-fidelity speakers, according to your space and needs, ranging from about Rs 16,000 a pair to Rs 25 lakh and above for top-notch HT speakers.

A/V Receivers
The heart of your home theatre system, these units receive audio and video signals from sources such as your Blu-ray player or DTH connection and decodes, amplifies and splits them into audio outputs that constitute your HT System.

If you are a first-timer, choose your A/V receiver according to your budget and requirements and then go shopping for a speaker set-up. If you're looking to upgrade your existing home theatre set-up, here are a couple of things you should keep in mind.

Channels – If you have had an amp that supports a 5.1 speaker set-up, upgrade to an amplifier that supports a 7.1 channel system. This will enable decoding and playback of movie audio tracks in a 7.1 speaker set-up thus enriching the overall home cinema experience, because these amps, most often, also offer additional features and decoding for newer formats. If you're picking up an amp for the first time, a 7.1 enabled amp is more or less a future-proof option.

Audio Formats – Most amps in the market will support Dolby Digital, Dolby Pro Logic IIx and/or DTS technology to enhance your surround sound experience. To get a taste of high-def audio, the amplifier should ideally support the latest HD audio formats such as Dolby TrueHD, Dolby Digital Plus and DTS HD Master Audio. These formats are completely uncompressed, which means that the audio rendered at home will be almost as good as the original recording.

At the classiest end of the spectrum, you can opt for a THX certified system that is widely claimed to provide the most unparalleled sound experience you can have at home. These amps meet stringent acoustic standards to deliver this experience and can cost a bomb.

Upscaling – With high-def content catching on like wildfire, go for an amplifier that can upscale your videos to HDMI. This basically means that the amplifier should be able to upscale non-HD content from DVDs or CDs and play it back in HD-like resolution on your display.

You might also want to look for other capabilities such as de-interlacing i.e. upgrading an interlaced video signal (1080i) to progressive scan (1080p) and scaling i.e. upgrading video to a better resolution within the same format.

Inputs and Outputs – The amp should have enough jacks to connect all your input and output devices, and cover all varieties of cables that you might require.

For audio sources, there should be inputs for co-axial cables and optical ones, S-video and component video for video playback and HDMI switching for both audio and video.

Add-ons – If you are going full Monty, you might as well pick one that has USB ports to plug and play content, radio and iPod connectivity, maybe even Bluetooth and Ethernet support. This makes the experience less complicated and more seamless.

Decently-powered A/V receivers that upscale to HDMI can cost upwards of Rs 55,000. Companies like Denon, Marantz and Onkyo are some of the brands you can consider.

Cables
Reserve at least 10 per cent of your HT system budget to spend on the cables that connect the various components, for they can make or mar your home theatre experience.

Their role is more significant than just connecting one system to another. The material, length and thickness of the cables used determine how efficiently power, video and audio are transmitted, and how clear and pristine the audio-visual experience is.

Cable gauge – Indicating the wire's thickness, the lower the cable gauge value the better is the capacity of the wire to transmit the audio signal. Expressed in AWG or American Wire Gauge, a 16 AWG is a decent size to have for a small set-up. The ideal cable gauge varies depending on the distance between your amplifier and speakers.

The right cable gauge, apart from enabling a richer sound experience will also dissipate heat better and will prevent your components from undergoing any strain or heat build-up.

Material – Flashback to chemistry class in school, and you might remember the teacher telling you that copper is a good conductor. The best speaker cables are copper wires coated so that they do not get oxidised. Hence, go for ones that say ‘OFC' on the label, OFC stands for Oxygen-free cables. A step higher and you must be looking for OFCs with gold plated plugs.

QED, Monster Cable and Profigold are some companies that have good quality cables on offer in Indian stores.